It is known that blends containing AES rubbers and AES resins are weather resistant, but their mechanical properties at low temperatures are unsatisfactory. At temperatures below 0° C. they become brittle and have unsatisfactory toughness which prevents these molding compositions from being used at lower temperatures. In particular the notched impact resistance of AES blends at low temperatures is poor in particular in comparison with acryl/butadiene/styrene (ABS) blends.
EP-A 0 502 367 relates to the production of AES-graft polymers and a copolymer, the copolymer containing 60 to 76 wt. % of an aromatic monomer of the vinyl type and 40 to 24% of an aliphatic copolymer. Vinyl aromatics and/or vinyl aromatics and vinyl cyanides substituted in the ring and/or (meth)acrylic acid-(C1–C8)-alkyl esters are grafted on. These thermoplastic copolymers should, amongst other things, have good impact resistance in addition to the desired good gloss, weather-resistance and anti-friction characteristics.
JP-A 50 109 247 discloses polycarbonate blends containing AES, which contain 0.1 to 10 wt. % liquid paraffin. JP-A 58 098 354 discloses polycarbonate blends containing AES and 0.5 to 20 wt. % plasticizers for vinyl polymers. It is not known that the use of special additives, which concentrate specifically in the soft phase of the blend, significantly improves low-temperature properties in polycarbonate AES blends.
The object of the invention is to modify AES blends in such a way that they have improved low-temperature properties, in particular improved notched impact resistance, whilst retaining their weather resistance.